Which I think we can all agree is more work than what we currently need to.

It's not just one addition, it's 2 operations following knowing what time midnight is to understand what the solar time it is: what time is it now, minus what time is their midnight, and then you have to add that back to what your midnight is to get a sense of the time. Or you just start thinking in solar time WHICH IS WHAT WE ALREADY DO.

That's 2 calculations. Currently we do 0.

Innately knowing what time means in films, talking to people over the phone, going to a new country. It would be a huge pain in the arse.

"They met up at 13:00“ great. So where are they in this film? Forcing exposition where currently you might let it be vague.

People who advocate for one timezone simply haven't thought it through.